Three lights flash at intervals of 4, 6 and 10 seconds respectively. They are started together. How soon after will they next flash together again?

The following diagram shows a model used to show how breathing movements take place:

Which part of the model represents the diaphragm?

In the circle above, the circumference is 20 cm. The length of the arc AB, in centimetres, is

Which one of the following is a biological component of a pond ecosystem?

THE ITEM refer to the following family functions.

The family produces children and maintains the population.

A salt that contains water of crystallisation is:

A contractor completed five-ninths of a job before a second contractor completed an additional one-third. What fraction of the job is left undone?

The animals shown in the diagram were identified using a dichotomous key based on the visible characteristics listed below:
Ⅰ body shape
Ⅱ number of legs
Ⅲ number of wings
Ⅳ number of eyes
Ⅴ number of antennae
Which characteristics could be used to divide the animals into two groups?

When solid carbon dioxide turns straight into a gas we call it:

The statements refer to a fuse. Which one is true?

A circular hole with diameter 4 cm is cut out of a circular piece of card with a diameter of 16 cm. The area of the remaining card, in cm² , is

Cooking food improves all of these EXCEPT for:

Which of the following statements about aerobic respiration is correct?

The empirical formula, C₆H₁₂O₆, gives the simplest ratio as:

Which of the following are all deficiency diseases?

Which one of the following statements about diffraction is true?

When carbon dioxide gas passes through limewater, the limewater:

The optimum temperature for enzyme action is:

Which of the relations represented below are functions?

The following are all natural materials EXCEPT for: